Various file folder supports of the prior art have utilized rails and folders suspended therefrom; however, such prior art devices have not been readily adapted for use in combination with open shelf filing cabinets, particularly due to the fact that most folder supporting rails and bars are so constructed that it is necessary to move the file folders and bars directly upward to a position above the supporting rails in order to remove the respective file folder from the file.
Due to the economy of open shelf filing systems and due to the desirability thereof with respect to office space, there has been an economic trend toward open shelf filing. Most conventional open shelf filing systems have therefore been provided with superimposed shelves and file folders are merely stacked side by side and tend to fall over or lean against each other without proper means for suspending them. Additionally the proper filing of large documents such as groups of blueprints and maps have posed a problem since most of these documents have been placed in large drawers wherein the sheets are laid flat or such documents have been stored in cubby-holes in a generally rolled condition. Various other inconvenient means and methods have been used to support such large documents, as for example clamps and hooks have been used to hange these large documents; however, such means and methods have been inconvenient and relatively inefficient.
.Iadd.More specifically, rail supported hangers with clamping devices for large documents are disclosed in U.S. Pat. No. 2,869,210 and Great Britain Pat. No. 655,910 the latter disclosing a hanger with a pair of clamping rails formed with mating zig zag vertical profiles to securely grip an upper edge of a plan, drawing or map therebetween. In U.S. Pat. No. 3,298,374 and Netherlands Pat. No. 6,706,044 there are disclosed hangers with opposite hinged portions extending on opposite sides of a document or group of documents with tongues or prongs from one portion extending through holes in the documents; the Netherlands patent showing a head on a prong interlocking with a horizontal slot in the opposite portion. U.S. Pat. No. 3,684,340 and France Pat. No. 731,238 disclose hangers for documents with lower planar portions having holes therein together with binding posts through the holes in the hanger and holes in a document, or folding fasteners extending through the holes in the hanger and holes in a document, to secure the documents to the hanger. These types of hanger arrangements have several deficiencies such as failing to occupy the minimum amount of space, being relatively more difficult to attach documents thereto, not offering adequate vertical and horizontal strength, or being relatively more expensive.
In suspended file folder systems, U.S. Pat. No. 2,935,204 shows the removal of a pair of supporting bars and attached folder by moving the bars and folder toward the rear, tipping the front ends of the bars below a front rail, and then moving the bar and folder beneath the front rail from the filing system; however such bars must be lifted at both ends to disengage notches in such ends from respective front and back rails prior to moving the bar and folder toward the rear; the lifting of the rear end can be difficult when the bar and folder can only be gripped at the front and the folder contains heavy documents. A stiffening rib or flange formed by a folded back upper edge of a supporting bar is illustrated in U.S. Pat. No. 2,749,915; such folded back edges increase the thickness of the supporting bars to more than twice the sheet material of which there are formed and thus take up extra space lessening the number of hangers per unit of horizontal space. The securement of edge portions of folders by strips integral with one half of the folder extending through horizontal slots in the opposite half of the folder is disclosed in Great Britain Pat. No. 890,810.
The prior art also contains various fastening devices which have little if any relevance to arrangements for hanging documents on rails; such fastening devices include U.S. Pat. No. 3,318,354 which illustrates a key secured by a strip including a head having opposite shoulders interlocking with opposite sides of an opening having a vertical slot portion, and U.S. Pat. No. 3,765,110 which discloses a plastic filament with end bars joined in a T-arrangement therewith to attach a tag to merchandise. .Iaddend.